Evidence-based Medicine

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: https://info.ahrq.gov. Let us know the nature of the problem, the Web address of what you want, and your contact information.

Atrial fibrillation (AF) is the most common type of heart rhythm abnormality that physicians see. Overall, patients with AF die twice as often as those without AF. Also, AF is considered the cause of stroke in 24 percent of people aged 80 to 89 years. There is little guidance based on scientific evidence to inform doctors about the best medications to convert AF into normal heart rhythm.

A recent study comparing various medications found that ibutilide and dofetilide—which are new class III antiarrhythmic agents currently undergoing extensive trials—and flecainide, another agent commonly used for treating AF, most effectively converted AF to normal heart rhythm when compared with control treatment (placebo, verapamil, diltiazem, or digoxin). However, data are not available on the long-term use of these medications in everyday clinical practice, cautions Marlene R. Miller, M.D., M.Sc., formerly of Johns Hopkins University and now with the Agency for Healthcare Research and Quality.

Dr. Miller and her colleagues at the AHRQ-supported Evidence-based Practice Center (EPC) at https://www.ahrq.gov/research/findings/evidence-based-reports/centers/index.html#johns (contract 290-97-0006) performed a meta-analysis of 36 studies of non-postoperative AF conversion to or maintenance of normal cardiac sinus rhythm in adults. Compared with control treatment, the likelihood or odds ratio (OR) for conversion was greatest for ibutilide/dofetilide (OR 29.1) and flecainide (OR 24.7). Less strong but conclusive evidence existed for propafenone (OR 4.6). Quinidine (OR 2.9) had moderate evidence of conversion efficacy. Disopyramide (OR 7.0) and amiodarone (OR 5.7) had evidence suggestive of efficacy. Sotalol (OR 0.4) had evidence suggestive of negative efficacy.

For maintenance of normal sinus rhythm, strong evidence of efficacy existed for quinidine (OR 4.1), disopyramide (OR 3.4), flecainide (OR 3.1), propafenone (OR 3.7), and sotalol (OR 7.1). Unfortunately, direct comparisons of medications and adverse event data were limited. The authors call for more research that directly compares these medications with each other and with electrical cardioversion and that better quantifies adverse event rates.

See "Efficacy of agents for pharmacologic conversion of atrial fibrillation and subsequent maintenance of sinus rhythm," by Dr. Miller, Robert L. McNamara, M.D., M.H.S., Jodi B. Segal, M.D., M.P.H., and others in the November 2000 Journal of Family Practice 49(11), pp. 1033-1046.

Editor's Note: This journal article is based on an evidence report prepared for AHRQ by the Johns Hopkins University EPC. A summary of Evidence Report/Technology Assessment No. 12, Management of New Onset Atrial Fibrillation (AHRQ Publication No. 00-E006), is now available from the AHRQ Publications Clearinghouse. The full report (AHRQ Publication No. 01-E026) is in press and will be available from AHRQ in the near future.